419 research outputs found

    Diamond: The Game – a board game for secondary school students promoting scientific careers and experiences

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    Diamond: The Game is a board game designed for secondary school students (aged 11–18) to enable them to explore a broad variety of science, technology, engineering and mathematics (STEM) careers, STEM subjects and life as a scientist. Board games are a reusable and entertaining way to directly engage students in STEM, but careful consideration of mechanics, messages and accessibility is required to successfully deliver on this goal. Diamond: The Game was designed and evaluated against these considerations. The inclusive approach to design resulted in a better and more accessible game for all. Its success is further evident in the rise in the number of players who would consider a career as a scientist or an engineer after playing. The opportunities to explore collaboration, failure and the interdisciplinary nature of science in the game were particularly highlighted in discussions with students, teachers and careers advisers

    A Precision Calculation of the Next-to-Leading Order Energy-Energy Correlation Function

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    The O(alpha_s^2) contribution to the Energy-Energy Correlation function (EEC) of e+e- -> hadrons is calculated to high precision and the results are shown to be larger than previously reported. The consistency with the leading logarithm approximation and the accurate cancellation of infrared singularities exhibited by the new calculation suggest that it is reliable. We offer evidence that the source of the disagreement with previous results lies in the regulation of double singularities.Comment: 6 pages, uuencoded LaTeX and one eps figure appended Complete paper as PostScript file (125 kB) available at: http://www.phys.washington.edu/~clay/eecpaper1/paper.htm

    Causality constraints in AdS/CFT from conformal collider physics and Gauss-Bonnet gravity

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    We explore the relation between positivity of the energy constraints in conformal field theories and causality in their dual gravity description. Our discussion involves CFTs with different central charges whose description, in the gravity side, requires the inclusion of quadratic curvature corrections. It is enough, indeed, to consider the Gauss-Bonnet term. We find that both sides of the AdS/CFT correspondence impose a restriction on the Gauss-Bonnet coupling. In the case of 6d supersymmetric CFTs, we show the full matching of these restrictions. We perform this computation in two ways. First by considering a thermal setup in a black hole background. Second by scrutinizing the scattering of gravitons with a shock wave in AdS. The different helicities provide the corresponding lower and upper bounds. We generalize these results to arbitrary higher dimensions and comment on some hints and puzzles they prompt regarding the possible existence of higher dimensional CFTs and the extent to which the AdS/CFT correspondence would be valid for them.Comment: 31 pages, 5 figures; v2: typos fixed, cosmetic amendments and references adde

    Versatile regularisation toolkit for iterative image reconstruction with proximal splitting algorithms

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    Ill-posed image recovery requires regularisation to ensure stability. The presented open-source regularisation toolkit consists of state-of-the-art variational algorithms which can be embedded in a plug-and-play fashion into the general framework of proximal splitting methods. The packaged regularisers aim to satisfy various prior expectations of the investigated objects, e.g., their structural characteristics, smooth or non-smooth surface morphology. The flexibility of the toolkit helps with the design of more advanced model-based iterative reconstruction methods for different imaging modalities while operating with simpler building blocks. The toolkit is written for CPU and GPU architectures and wrapped for Python/MATLAB. We demonstrate the functionality of the toolkit in application to Positron Emission Tomography (PET) and X-ray synchrotron computed tomography (CT)

    BRCA1 and BRCA2 mutations in a population-based study of male breast cancer

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    Background: The contribution of BRCA1 and BRCA2 to the incidence of male breast cancer (MBC) in the United Kingdom is not known, and the importance of these genes in the increased risk of female breast cancer associated with a family history of breast cancer in a male first-degree relative is unclear. Methods: We have carried out a population-based study of 94 MBC cases collected in the UK. We screened genomic DNA for mutations in BRCA1 and BRCA2 and used family history data from these cases to calculate the risk of breast cancer to female relatives of MBC cases. We also estimated the contribution of BRCA1 and BRCA2 to this risk. Results: Nineteen cases (20%) reported a first-degree relative with breast cancer, of whom seven also had an affected second-degree relative. The breast cancer risk in female first-degree relatives was 2.4 times (95% confidence interval [CI] = 1.4–4.0) the risk in the general population. No BRCA1 mutation carriers were identified and five cases were found to carry a mutation in BRCA2. Allowing for a mutation detection sensitivity frequency of 70%, the carrier frequency for BRCA2 mutations was 8% (95% CI = 3–19). All the mutation carriers had a family history of breast, ovarian, prostate or pancreatic cancer. However, BRCA2 accounted for only 15% of the excess familial risk of breast cancer in female first-degree relatives. Conclusion: These data suggest that other genes that confer an increased risk for both female and male breast cancer have yet to be found

    The agency of liminality: army wives in the DR Congo and the tactical reversal of militarization

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    The inherently unstable boundaries between military and civilian worlds have emerged as a main object of study within the field of critical military studies. This article sheds light on the (re)production of these boundaries by attending to a group that rarely features in the debates on the military/civilian divide: army wives in a ‘non-Northern’ context, more specifically the Democratic Republic of the Congo (DRC). Drawing upon the ‘analytical toolbox’ of governmentality, we explore how civilian and military positionalities are called upon, articulated and subverted in the governing and self-governing of Congolese army wives. We show the decisive importance of these wives’ civilian-military ‘in betweenness’ both in efforts to govern them and in their exercise of agency, in particular The inherently unstable boundaries between military and civilian worlds have emerged as a main object of study within the field of critical military studies. This article sheds light on the (re)production of these boundaries by attending to a group that rarely features in the debates on the military/civilian divide: army wives in a ‘non-Northern’ context, more specifically the Democratic Republic of the Congo (DRC). Drawing upon the ‘analytical toolbox’ of governmentality, we explore how civilian and military positionalities are called upon, articulated, and subverted in the governing and self-governing of Congolese army wives. We show the decisive importance of these wives’ civilian–military ‘in-betweenness’ both in efforts to govern them and in their exercise of agency, in particular the ways in which they ‘tactically reverse’ militarization. The article also demonstrates the dispersed nature of the governing arrangements surrounding army wives, highlighting the vital role of ‘the civilian’ as well as the ‘agency of those being militarized’ within processes of militarization. By foregrounding the relevance of studying Congolese army wives and their militarization with an analytical toolbox often reserved for so called ‘advanced militaries/societies’, and by revealing numerous similarities between the Congolese and ‘Northern’ contexts, the article also sets out to counter the Euro/US-centrism and ‘theoretical discrimination’ that mark present-day (critical) military studies

    IL-23 drives a pathogenic T cell population that induces autoimmune inflammation

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    Interleukin (IL)-23 is a heterodimeric cytokine composed of a unique p19 subunit, and a common p40 subunit shared with IL-12. IL-12 is important for the development of T helper (Th)1 cells that are essential for host defense and tumor suppression. In contrast, IL-23 does not promote the development of interferon-γ–producing Th1 cells, but is one of the essential factors required for the expansion of a pathogenic CD4+ T cell population, which is characterized by the production of IL-17, IL-17F, IL-6, and tumor necrosis factor. Gene expression analysis of IL-23–driven autoreactive T cells identified a unique expression pattern of proinflammatory cytokines and other novel factors, distinguishing them from IL-12–driven T cells. Using passive transfer studies, we confirm that these IL-23–dependent CD4+ T cells are highly pathogenic and essential for the establishment of organ-specific inflammation associated with central nervous system autoimmunity

    Optimizing for periodicity: a model-independent approach to flux crosstalk calibration for superconducting circuits

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    Flux tunability is an important engineering resource for superconducting circuits. Large-scale quantum computers based on flux-tunable superconducting circuits face the problem of flux crosstalk, which needs to be accurately calibrated to realize high-fidelity quantum operations. Typical calibration methods either assume that circuit elements can be effectively decoupled and simple models can be applied, or require a large amount of data. Such methods become ineffective as the system size increases and circuit interactions become stronger. Here we propose a new method for calibrating flux crosstalk, which is independent of the underlying circuit model. Using the fundamental property that superconducting circuits respond periodically to external fluxes, crosstalk calibration of N flux channels can be treated as N independent optimization problems, with the objective functions being the periodicity of a measured signal depending on the compensation parameters. We demonstrate this method on a small-scale quantum annealing circuit based on superconducting flux qubits, achieving comparable accuracy with previous methods. We also show that the objective function usually has a nearly convex landscape, allowing efficient optimization
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